Safety attachment for elevators.



.I. E. DUNN.

SAFETY ATTACHMENT FOR ELEVATORS.

APPLICATION FILED APR. 8 1914.

Patented Aug. 24, 1915.

2 SHEETS-SHEET I.

J. E. DUNN.

SAFETY ATTACHMENT FOR ELEVATORS.

APPLICATION FILED APR.3| 1914.

1, 1.51 ,094. Patented Aug. 24, 1915.

2 SHEETS-SHEET 2.

win am an COLUMBIA PLANDGRAPH c0.,wAsHlNuTON,D. c.

abl'ozucla JOHN E. DUNN, or nnwmnonNn, oo oRaDo.

SAFETY ATTACHMENT FOR ELEVATORS.

Specification of Letters Patent.

Patented Aug. 24, 1915.

Application filed April 8, 1914. Serial No. 830,506.

To all whom it may concern Be it known that 1, JOHN E. DUNN, a citizen of the United States, residing at Hawthorne, in the county of Boulder and State of Colorado, have invented certain new and useful Improvements in Safety Attachments for Elevators, of which the following is a specification.

This invention relates to a safety attachment for an elevator, and the principal object of the invention is to provide an attachment carried by the elevator so that if the cable breaks, the pinions engaging the rack teeth of the guiding bars mounted in the shaft may be locked thus preventing the elevator from dropping.

Another object of the invention is to provide an improved type of frame carried by the elevator, and to also provide improved means for slidably connecting the frame with the elevator car.

This invention is illustrated in the accompanying drawings wherein Figure 1 is a view showing the elevated car in elevation with the safety attachment in its normal position; Fig. 2 is a view showing the car in side elevation with the safety attachment applied thereto; Fig. 3 1s a perspective view of one of the pawls which engage the pinion carried by the car; Fig. 1 is a perspective view of one of the guides which slidably connect the frame with the car.

The frame 10 which is in the form of a metallic band, as clearly shown in Figs. 1 and 2, extends around the car 11, and is provided with an eye 12 with which the supporting cable 13 is connected.

Springs 1 1 are placed beneath the car and engage the frame, as shown in Fig. 1 so that if the cable breaks, the springs will move the frame downwardly and thus bring the safety device into operation. This frame passes over rollers 15 and under the cross heads 16 of the pins 17 which are secured to the sides of the car by suitable fastening rods or bolts which pass through openings formed in the base plates 18.

It should be noted that the frame is provided with slots 19 through which the pins 17 pass so that the frame may move vertically and thus move the clutches 19 into and out of operative position. These clutches which are secured to the frame by means of bolts or rivets passing through the openings in the base plates 20 are provided with teeth 21 which are intended to engage the teeth of the pinions 22 and prevent the pinions from rotating.

The pinions 22 are carried by axles 23 rotatably mounted in the bearing brackets 24 carried by the car 11. Under normalcircumstances the frame will be held in the raised position shown in Fig. 1, and therefore the pinions 22 can move freely along the rack bars 25; but when the cable 13 breaks, the springs 14 will move the frame downwardly and bring the clutches into engagement with the pinions so that the teeth of the clutches and pinions will interlock thus preventing the pinions from rotating and preventing them from moving along the rack bars 25. Since the teeth of the pinions will interlock with the teeth of the rack bars when the clutches engage the pinions, the car can not move downwardly in the elevator shaft and therefore there is no danger of the car dropping to the bottom of the shaft.

I have thus provided an elevator attachment which will not interfere with the movement of the car in the shaft when the cable is unbroken, but which will quickly stop the dropping of the car if the cable breaks.

What is claimed is:

1. An elevator car, rack bars positioned upon opposite sides of said car guiding rollers carried by said car, a frame extending about said car and engaging said rollers, said frame being provided with elongated slots means for connecting said frame with a suspending element, springs positioned between said frame and the bottom of said car for normally holding said frame in a lowered position, pins extending from said car through the elongated slots formed in said frame and provided with cross heads extending transversely of said frame to hold said frame in engagement with said rollers, bearing brackets carried by said car upon opposite sides of said frame, pinions engaging said rack bars and having their supporting axles rotatably carried by said bearing brackets and extending across said frame, and clutches carried by said frame and provided with teeth for interlocking with the teeth of said pinions when said frame is moved downwardly by said springs.

2. A car, rack bars, pinions rotatably connected with said car and engaging the teeth of said rack bars, clutches, supporting means for said clutches slidably connected with said car and provided with elongated slots,

rollers connected with said car and engaging said supporting means, means carried by said car and extending through said slots to hold said supporting means in engagement With said rollers, means for normally hold- Gopies of this patent may be obtained for ment With said rollersypinions rotatably 1-5 connected with said car and engaging said rack bars, clutches carried by said frame for engaging said pinions, and yieldable means normally holding said frame in a position to bring said clutches into engagement with said pinions.

In testimony whereof I affix my signature in presence of two witnesses.

JOHN E. DUNN.

WVitn'esses LAWRENCE E. CI-IENAULT, ROBERT W. JosLYN.

five cents each, by addressing the Commissioner of Patents,

Washington, I). 0. 

